反应详情

温度

80 °C

To a solution of n-butylmalonic acid (17.2 g, 107 mmol) in ethanol (200 ml) was added piperidine (12.76 ml, 129 mmol) and 37% aq. formaldehyde (40.3 ml, 538 mmol). The solution was heated to 80° C. during which time a precipitate appeared and gradually redissolved over 1 hour. The reaction mixture was stirred at 80° C. overnight then cooled to room temperature. The solvents were removed under reduced pressure and the residue was dissolved in ethyl acetate (200 ml), washed successively with 1 M hydrochloric acid and brine, dried over anhydrous magnesium sulfate and filtered. The filtrate was concentrated to give the title compound as a clear oil (13.37 g, 97%). 1H-NMR; δ (CDCl3), 6.29 (1H, s), 5.65 (1H, s), 2.34–2.28 (2H, m), 1.54–1.26 (4H, M), 0.94 (3H, t, J=7.1 Hz).

1. dissolutiongradually redissolved over 1 hour
2. temperaturethen cooled to room temperature
3. customThe solvents were removed under reduced pressure
4. dissolutionthe residue was dissolved in ethyl acetate (200 ml)
5. washwashed successively with 1 M hydrochloric acid and brine
6. dry with materialdried over anhydrous magnesium sulfate
7. filtrationfiltered
8. concentrationThe filtrate was concentrated